The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
/* * Copyright (C) 2008 The Android开源工程 * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.android.apis.graphics; import android.graphics.Canvas; import android.graphics.ColorFilter; import android.graphics.PixelFormat; import android.graphics.drawable.Drawable; public class ProxyDrawable extends Drawable { private Drawable mProxy; private boolean mMutated; public ProxyDrawable(Drawable target) { mProxy = target; } public Drawable getProxy() { return mProxy; } public void setProxy(Drawable proxy) { if (proxy != this) { mProxy = proxy; } } @Override public void draw(Canvas canvas) { if (mProxy != null) { mProxy.draw(canvas); } } @Override public int getIntrinsicWidth() { return mProxy != null ? mProxy.getIntrinsicWidth() : -1; } @Override public int getIntrinsicHeight() { return mProxy != null ? mProxy.getIntrinsicHeight() : -1; } @Override public int getOpacity() { return mProxy != null ? mProxy.getOpacity() : PixelFormat.TRANSPARENT; } @Override public void setFilterBitmap(boolean filter) { if (mProxy != null) { mProxy.setFilterBitmap(filter); } } @Override public void setDither(boolean dither) { if (mProxy != null) { mProxy.setDither(dither); } } @Override public void setColorFilter(ColorFilter colorFilter) { if (mProxy != null) { mProxy.setColorFilter(colorFilter); } } @Override public void setAlpha(int alpha) { if (mProxy != null) { mProxy.setAlpha(alpha); } } @Override public Drawable mutate() { if (mProxy != null && !mMutated && super.mutate() == this) { mProxy.mutate(); mMutated = true; } return this; } }